On 13/01/2026 18:19, Samuel Thibault wrote:
which makes sure to put the content of save_data on the stack instead of
in xmm0, while calling mach_msg().
So we have something that clobbers xmm0 somehow, and this is only a dumb
workaround that only avoids the issue in the notable but still
particular case of blocking RPCs.
This description might also apply to the similar situation that I am
seeing with the stress-ng tests. The asm generated from the stress-ng
code in function stress_vm_incdec makes use of a number of %xmm
registers.
Has this issue with signal handling been resolved?
I've seen some fixes in glibc (eg. hurd/x86_64/htl/pt-machdep.c) which
I've incorporated into a glibc referenced solely within my test program
(via suitable LD_LIBRARY_PATH to locate libc.so and libpthread.so) and
admittedly not system wide. I appreciate that this limitation might
affect the validity of this test environment.
In any case, I now have a standalone test case to reproduce the errors
that I saw in stress-ng but in a very simple standalone C program. This
could be useful if the issue is still outstanding.
Regards,
Mike.
